This disclosure relates generally to transportation of freight and in particular to the efficient and timely routing of heavy-duty trucks through a network of roads.
In the U.S., heavy-duty trucks haul more than 70% of all freight tonnage. They consume 17.6% of the energy used in the transportation sector and contribute about 5% of total greenhouse gas emissions. Fuel cost is the largest operating cost incurred by truck operators, and reducing fuel consumption is critical for cost-effective and environmentally-friendly heavy-duty truck operations.
Apart from fuel cost, timely delivery is another critical issue for truck operators. Unexpected delays can increase freight cost by 50% to 250%. Multiple factors contribute to the importance of timely delivery. For instance, some freight goods, such as food, are perishable and may become worthless if not timely delivered. As another example, to ensure customers' satisfaction, some shippers, e.g., Amazon, may have a service-level agreement (SLA) with customers, under which a delivery date is guaranteed; late deliveries directly cost the company money. In addition, even in the absence of a guarantee, late deliveries may be detrimental to customer relationships. Moreover, failing to deliver as scheduled may introduce difficulties for global logistics and may increase the uncertainty and inefficiency of supply chains.
Efforts have been made to make heavy-duty trucks more fuel efficient. Examples include improvements to designs for engines, drivetrains, aerodynamics, and tires, as well as improved maintenance procedures such as maintaining optimal tire pressure. However, outside of these physical design and maintenance changes, there is an opportunity to increase efficiency by optimizing heavy-duty truck operations.